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HSQL 数据库介绍(2)--使用

2024-07-14 22:31 由 且行且码 发表于 #后端开发

本文主要介绍 HSQLDB 的基本使用，文中所使用到的软件版本：Java 11.0.22、HSQLDB 2.7.2。

1、进程内模式

直接使用 JDBC 连接数据库即可，如果数据库不存在会自动创建。

1.1、file 数据库

@Test
public void inProcessFile() throws SQLException {
    String dbName = "test";
    //用户名密码为第一次连接设置的密码
    Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:file:d:/temp/" + dbName, "admin", "123456");
    log.info("con={}", con);
    business(con);
    con.close();
}

private void business(Connection con) throws SQLException {
    String tableName = "a_student";
    Statement st = con.createStatement();
    String sql = "select 1 from INFORMATION_SCHEMA.TABLES where upper(table_schema)=? and upper(table_name)=?";
    PreparedStatement pst = con.prepareStatement(sql);
    pst.setString(1, "PUBLIC");
    pst.setString(2, tableName.toUpperCase());
    ResultSet rs = pst.executeQuery();
    if (!rs.next()) {//表不存在则创建并初始化数据，这里根据业务需要进行操作
        st.executeUpdate("create table " + tableName + "(id int, name varchar(32))");
        st.executeUpdate("insert into " + tableName + "(id,name) values (1,'李白')");
        st.executeUpdate("insert into " + tableName + "(id,name) values (2,'杜甫')");
    }

    rs = st.executeQuery("select * from " + tableName);
    while (rs.next()) {
        log.info("id={},name={}", rs.getInt("id"), rs.getString("name"));
    }
}

1.2、mem 数据库

@Test
public void inProcessMem() throws SQLException {
    String dbName = "test";
    //用户名密码为第一次连接设置的密码
    Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:mem:" + dbName, "admin", "123456");
    log.info("con={}", con);
    business(con);
    con.close();
}

1.3、res 数据库

@Test
public void inProcessRes() throws SQLException {
    String dbName = "test";
    //用户名密码为第一次连接设置的密码,数据库文件位于某个依赖 jar 文件的 db 目录中
    Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:res:db/" + dbName, "admin", "123456");
    log.info("con={}", con);
    business(con);
    con.close();
}

2、服务器模式

2.1、HyperSQL HSQL Server

可以通过如下命令启动 HyperSQL HSQL Server，假设当前位于 HSQLDB 安装包的 data 目录中：

java -cp ../lib/hsqldb.jar org.hsqldb.server.Server --database.0 file:d:/temp/mydb --dbname.0 test #启动file数据库，数据库文件保存在d:/temp目录下，数据名称为 test
java -cp ../lib/hsqldb.jar org.hsqldb.server.Server --database.0 mem:mydb --dbname.0 test #启动mem数据库，数据名称为 test

可以添加其他参数来调整数据库的默认行为，查看所有参数：

java  -cp ../lib/hsqldb.jar org.hsqldb.server.Server --help

相关参数如下：

Usage: java org.hsqldb.server.WebServer [options]

+-----------------+------------ +------------+------------------------------+
|     OPTION      |    TYPE     |  DEFAULT   |         DESCRIPTION          |
+-----------------+-------------+------------+------------------------------|
| --help          | -           | -          | displays this message        |
| --address       | name|number | any        | server inet address          |
| --port          | number      | 80/443     | port at which server listens |
| --database.i    | [type]spec  | 0=test     | name of database i           |
| --dbname.i      | alias       | -          | url alias for database i     |
| --root          | path        | ./         | path to web root             |
| --default_page  | file        | index.html | default web page             |
| --silent        | true|false  | true       | false => display all queries |
| --trace         | true|false  | false      | display JDBC trace messages  |
| --tls           | true|false  |            | HTTPS (secure) sockets       |
| --no_system_exit| true|false  | false      | do not issue System.exit()   |
| --remote_open   | true|false  | false      | can open databases remotely  |
| --props         | filepath    |            | file path of properties file |
+-----------------+-------------+------------+------------------------------+

The web server looks for a 'webserver.properties' file in the current directory
and loads properties from it if it exists.
Command line options override those loaded from the 'webserver.properties' file.

启动后使用 JDBC 访问数据库：

@Test
public void hsqlServer() throws SQLException {
    String dbName = "test";
    Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:hsql://localhost:9001/" + dbName, "SA", "");
    log.info("con={}", con);
    business(con);
    con.close();
}

2.2、HyperSQL HTTP Server

可以通过如下命令启动 HyperSQL HTTP Server，假设当前位于 HSQLDB 安装包的 data 目录中：

java -cp ../lib/hsqldb.jar org.hsqldb.server.WebServer --database.0 file:d:/temp/mydb --dbname.0 test #启动file数据库，数据库文件保存在d:/temp目录下，数据名称为 test
java -cp ../lib/hsqldb.jar org.hsqldb.server.WebServer --database.0 mem:mydb --dbname.0 test #启动mem数据库，数据名称为 test

可以添加其他参数来调整数据库的默认行为，查看所有参数：

java  -cp ../lib/hsqldb.jar org.hsqldb.server.WebServer --help

相关参数如下：

Usage: java org.hsqldb.server.WebServer [options]

+-----------------+------------ +------------+------------------------------+
|     OPTION      |    TYPE     |  DEFAULT   |         DESCRIPTION          |
+-----------------+-------------+------------+------------------------------|
| --help          | -           | -          | displays this message        |
| --address       | name|number | any        | server inet address          |
| --port          | number      | 80/443     | port at which server listens |
| --database.i    | [type]spec  | 0=test     | name of database i           |
| --dbname.i      | alias       | -          | url alias for database i     |
| --root          | path        | ./         | path to web root             |
| --default_page  | file        | index.html | default web page             |
| --silent        | true|false  | true       | false => display all queries |
| --trace         | true|false  | false      | display JDBC trace messages  |
| --tls           | true|false  |            | HTTPS (secure) sockets       |
| --no_system_exit| true|false  | false      | do not issue System.exit()   |
| --remote_open   | true|false  | false      | can open databases remotely  |
| --props         | filepath    |            | file path of properties file |
+-----------------+-------------+------------+------------------------------+

The web server looks for a 'webserver.properties' file in the current directory
and loads properties from it if it exists.
Command line options override those loaded from the 'webserver.properties' file.

启动后使用 JDBC 访问数据库：

@Test
public void httpServer() throws SQLException {
    String dbName = "test";
    Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:http://localhost:80/" + dbName, "SA", "");
    log.info("con={}", con);
    business(con);
    con.close();
}

2.3、HyperSQL HTTP Servlet

这种方式使用较少，这里就不详细介绍，可参考源文件 src/org/hsqldb/server/Servlet.java 查看详细信息。

3、混合模式

应用通过代码的方式启动数据库服务，应用内访问数据库可以使用进程模式，其他应用通过服务器模式访问。下面衍生通过代码分别启动 HyperSQL HSQL Server 和 HyperSQL HTTP Server，然后模拟其他应用访问数据库。

3.1、HyperSQL HSQL Server

@Test
public void hsqlServer2() throws Exception {
    HsqlProperties p = new HsqlProperties();
    //三种数据库类型，根据需要选择合适的一个
    p.setProperty("server.database.0","file:d:/temp/mydb");
    //p.setProperty("server.database.0","mem:mydb");
    //p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中
    p.setProperty("server.dbname.0","test");
    Server server = new Server();
    server.setProperties(p);
    server.start();

    CountDownLatch countDownLatch = new CountDownLatch(1);
    new Thread(() -> {
        try {
            //模拟其他应用访问
            hsqlServer();
        } catch (Exception e) {
            e.printStackTrace();
        }
        countDownLatch.countDown();
    }).start();
    countDownLatch.await();

    server.shutdownCatalogs(1);
    server.stop();
}

Server 的属性配置参数可参考 2.1 中启动数据库时的命令行参数。

3.2、HyperSQL HTTP Server

@Test
public void httpServer2() throws Exception {
    HsqlProperties p = new HsqlProperties();
    //三种数据库类型，根据需要选择合适的一个
    //p.setProperty("server.database.0","file:d:/temp/mydb");
    //p.setProperty("server.database.0","mem:mydb");
    p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中
    p.setProperty("server.dbname.0","test");

    WebServer webServer = new WebServer();
    webServer.setProperties(p);
    webServer.start();
    
    CountDownLatch countDownLatch = new CountDownLatch(1);
    new Thread(() -> {
        try {
            //模拟其他应用访问
            httpServer();
        } catch (Exception e) {
            e.printStackTrace();
        }
        countDownLatch.countDown();
    }).start();
    countDownLatch.await();

    webServer.stop();
}

WebServer 的属性配置参数可参考 2.2 中启动数据库时的命令行参数。

 

完整代码：

package com.abc.demo.db;

import lombok.extern.slf4j.Slf4j;
import org.hsqldb.Server;
import org.hsqldb.persist.HsqlProperties;
import org.hsqldb.server.WebServer;
import org.junit.Test;

import java.sql.*;
import java.util.concurrent.CountDownLatch;

@Slf4j
public class HSQLCase {
    @Test
    public void inProcessFile() throws SQLException {
        String dbName = "test";
        //用户名密码为第一次连接设置的密码
        Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:file:d:/temp/" + dbName, "admin", "123456");
        log.info("con={}", con);
        business(con);
        con.close();
    }

    @Test
    public void inProcessMem() throws SQLException {
        String dbName = "test";
        //用户名密码为第一次连接设置的密码
        Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:mem:" + dbName, "admin", "123456");
        log.info("con={}", con);
        business(con);
        con.close();
    }

    @Test
    public void inProcessRes() throws SQLException {
        String dbName = "test";
        //用户名密码为第一次连接设置的密码,数据库文件位于某个依赖 jar 文件的 db 目录中
        Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:res:db/" + dbName, "admin", "123456");
        log.info("con={}", con);
        business(con);
        con.close();
    }

    @Test
    public void hsqlServer() throws SQLException {
        String dbName = "test";
        Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:hsql://localhost:9001/" + dbName, "SA", "");
        log.info("con={}", con);
        business(con);
        con.close();
    }

    @Test
    public void httpServer() throws SQLException {
        String dbName = "test";
        Connection con = JdbcUtil.getConnection("org.hsqldb.jdbc.JDBCDriver", "jdbc:hsqldb:http://localhost:80/" + dbName, "SA", "");
        log.info("con={}", con);
        business(con);
        con.close();
    }

    @Test
    public void hsqlServer2() throws Exception {
        HsqlProperties p = new HsqlProperties();
        //三种数据库类型，根据需要选择合适的一个
        p.setProperty("server.database.0","file:d:/temp/mydb");
        //p.setProperty("server.database.0","mem:mydb");
        //p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中
        p.setProperty("server.dbname.0","test");
        Server server = new Server();
        server.setProperties(p);
        server.start();

        CountDownLatch countDownLatch = new CountDownLatch(1);
        new Thread(() -> {
            try {
                //模拟其他应用访问
                hsqlServer();
            } catch (Exception e) {
                e.printStackTrace();
            }
            countDownLatch.countDown();
        }).start();
        countDownLatch.await();

        server.shutdownCatalogs(1);
        server.stop();
    }

    @Test
    public void httpServer2() throws Exception {
        HsqlProperties p = new HsqlProperties();
        //三种数据库类型，根据需要选择合适的一个
        //p.setProperty("server.database.0","file:d:/temp/mydb");
        //p.setProperty("server.database.0","mem:mydb");
        p.setProperty("server.database.0","res:db/test");//数据库文件test.xx位于某个依赖jar文件的 db 目录中
        p.setProperty("server.dbname.0","test");

        WebServer webServer = new WebServer();
        webServer.setProperties(p);
        webServer.start();

        CountDownLatch countDownLatch = new CountDownLatch(1);
        new Thread(() -> {
            try {
                //模拟其他应用访问
                httpServer();
            } catch (Exception e) {
                e.printStackTrace();
            }
            countDownLatch.countDown();
        }).start();
        countDownLatch.await();

        webServer.stop();
    }

    private void business(Connection con) throws SQLException {
        String tableName = "a_student";
        Statement st = con.createStatement();
        String sql = "select 1 from INFORMATION_SCHEMA.TABLES where upper(table_schema)=? and upper(table_name)=?";
        PreparedStatement pst = con.prepareStatement(sql);
        pst.setString(1, "PUBLIC");
        pst.setString(2, tableName.toUpperCase());
        ResultSet rs = pst.executeQuery();
        if (!rs.next()) {//表不存在则创建并初始化数据，这里根据业务需要进行操作
            st.executeUpdate("create table " + tableName + "(id int, name varchar(32))");
            st.executeUpdate("insert into " + tableName + "(id,name) values (1,'李白')");
            st.executeUpdate("insert into " + tableName + "(id,name) values (2,'杜甫')");
        }

        rs = st.executeQuery("select * from " + tableName);
        while (rs.next()) {
            log.info("id={},name={}", rs.getInt("id"), rs.getString("name"));
        }
    }
}
HSQLCase.java
package com.abc.demo.db;

import lombok.extern.slf4j.Slf4j;

import java.sql.*;


@Slf4j
public class JdbcUtil {
    private JdbcUtil() {}

    public static Connection getConnection(String driver, String url, String username, String password) {
        Connection con = null;
        try {
            Class.forName(driver);
            con = DriverManager.getConnection(url, username, password);
        } catch (ClassNotFoundException | SQLException e) {
            log.warn("url={},username={},password={}", url, username, password);
            e.printStackTrace();
        }
        return con;
    }
}
JdbcUtil.java

 

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